Stock feeder

ABSTRACT

A simplified low-cost air-operated stock feeder for punch presses, and having a separate three-way valve unit which is detachable from the rest of the feeder and which is adapted to apply to stock being fed a clamping force corresponding to the force required to operate the valve unit. Fluid pressure is conducted to and from the feeder air motors through a simple flexible tube that is connected between the reciprocating feed slide and the output port of said valve unit. A tubular main air motor is coaxially mounted on one of two slide rods forming part of the feeder frame.

United States Patent 6/1962 Nordlof 226/162X Primary Examiner-Allen N. Knowles ABSTRACT: A simplified low-cost air-operated stock feeder for punch presses, and having a separate three-way valve unit which is detachable from the rest of the feeder and which is adapted to apply to stock being fed a clamping force corresponding to the force required to operate the valve unit. Fluid pressure is conducted to and from the feeder air motors through a simple flexible tube that is connected between the reciprocating feed slide and the output port of said valve unit. A tubular main air motor is coaxially mounted on one of two slide rods forming part of the feeder frame.

PATENIEU FEB SIB?! 3561.657

sum 20F 2 This invention relates to a novel low-cost air-operated stock feeder for punch presses and the like. More particularly the invention relates to a novel and very much simplified reciprocating-type air feeder for intermittently advancing strip stock into the work station of a punch press.

The currently available air-operated stock feeders are relatively expensive by reason of being made from parts that are either complex in design or are excessively numerous, or both. The instant invention contemplates the provision of a greatly simplified feeder wherein only a relative few inexpensive parts are required, these parts being readily assembled so as to afford an exceptionally low-cost but efficient air-operated stock feeding device.

One object of the instant invention is to provide a low-cost air-operated stock feeder wherein a fluid-valving function and a stock-clamping function may both be afforded by a single unit.

Another object of the invention is to provide a novel stockfeeding device wherein a complete valving unit may be readily detached therefrom for use with other similar stock feeders.

Another object of the invention is to provide a very simplified stock-feeding device wherein a single fluid conduit line is operatively coupled to the reciprocating feed slide of the device so as to supply and exhaust fluid pressure to and from the feeder air motors that cause said stock to be gripped and advanced in a feed direction.

Another object of the invention is to provide a novel stock feeder having a tubular stock-feeding air motor that is adjustably mounted on the feeder frame so as to be capable of determining the effective stroke length of the feeder and so as to minimize the fluid pressure conduits required for said air motor.

Other objects of the invention will become apparent as the disclosure progresses.

In the drawings:

FIG. 1 is a plan view of the instant stock feeder.

FIG. 2 is an elevational view in partial section taken along section line 2-2 of FIG. 3.

FIG. 3 is a front elevational view taken in partial section along section line 33 of FIG. 1.

FIG. 4 is a right side elevational view in partial section taken along section line 4-4 of FIG. 3.

FIG. 5 is a partial sectional view taken along section line 5-5 of FIG. 1.

FIG. 6 is a partially sectioned side elevational view corresponding to FIG. 2 and shows a modified embodiment of the feed slide of the instant device.

FIG. 7 is a side elevation view showing an adjustable mounting for the valve.

Referring now particularly to FIGS. 1-3 the instant feeder is provided with a rigid frame 10 comprising a pair of parallel slide rods 11 and 12 each having reduced threaded ends that are secured by suitable nuts to a forward block 13 made from standard channel iron and a rearward block 14 made from standard angle iron. Rod 12 carries a first or main fluid motor means 15 which includes a cylinder barrel 16 that is axially adjustably mounted on the rod 12 by means of a plug 17 that threadedly engages the left ends, as seen in FIGS. 1 and 3, of both the barrel 16 and the rod 12. A lock nut 20 secures the barrel in adjusted axial position along the said left or rearward portion ofrod 12. Slidably mounted in said barrel is a tubular piston 21 that is integrally connected to a tubular piston rod 22 that surrounds rod 12. To the forward end of piston rod 22 there is secured by means of a threaded cap 23, a feed block or slide 24 that carries a stock-gripping means 25. Sliding O- ring seals 26 and 27, FIG. 3, are provided between the said barrel and piston and between the said cap 23 and rod 12 respectively so that when pressure fluid (such as air) is introduced into the cylinder 30 of said motor means 15 the feed slide 24 will be advanced in a forward or stock-feeding direction 31, FIG. 1, and when fluid pressure is exhausted from said cylinder said feed slide may be moved in a rearward or indexing direction 32 by any suitable biasing means such as a spring 33, the latter being operatively connected in any suitable manner between the rearward block 14 and the feed slide 24.

The stock-gripping means 25 comprises a lever arm 34, FIG. 2, that is pivotally mounted on feed slide 24 for small angular displacements by means of a stud 35 that passes through a slightly enlarged hole in said lever arm and is threadedly secured in the top of said feed slide; a suitable hemispherical type thrust washer 36 being provided to facilitate the lever pivoting action. The lower rounded corner at the right-hand end, as seen in FIG. 2, of lever arm 34 is adapted to move between a lowered stock-gripping position and an upper stock release position shown in FIG. The opposite end of the lever is adapted to be power actuated in an upward direction by a second fluid motor means 37, the latter comprising a cylinder 40 formed in the feed block 24 and in which is slidably mounted a piston 41. Piston 41 is provided with a suitable sliding O-ring seal 42 and with an integral piston rod 43 that is formed with a reduced extension 44 that is disposed in a slightly enlarged retaining hole in said lever arm. As will be apparent when fluid pressure (such as air) is introduced into the lower portion of cylinder 40 lever arm 34 will be pivoted through a small angle so that the said right-hand end thereof is moved to a stock-gripping position, and when said fluid pressure is exhausted from cylinder 40 the lever arm will release its grip on the stock. If desired any suitable spring means may be used to urge said lever 34 to its stockreleasing position.

The feed slide 24 is also provided with a feed stroke impact buffer means 45 comprising a cylinder 46, FIGv 5, formed in the feed block and in which is slidably mounted a piston 47 having an integral piston rod 50 that extends forwardly through a slightly enlarged hole formed in the feed block. The piston 47 is provided with a suitable O-ring sliding seal, and the cylinder 46 is closed at its rearward end by means of a headed screw 51.

Fluid pressure is adapted to be supplied to said first and second fluid motor means 15 and 37 and to said buffer means 45 simultaneously through a single flexible tube that is operatively coupled to the feed block by means of a suitable threaded fitting 61. The feed slide or block 24 is formed with fluid-conducting passages which respectively lead from fitting 61 to said fluid motor and impact buffer means, and such includes a bore 62, lfig. 2, which extends inwardly to the feed block hole through which the piston rod 22 extends, and there communicates with an annular groove 63 formed in the immediately adjacent outer surface of said piston rod. Radial holes 64 and 65 formed in the central plane of said groove 63 serve to communicate said groove with the inside of said tubular piston rod 22. In that the inside diameter of the piston rod 22 is slightly greater than the outside diameter of the rod 12 there is thus provided a small annular passage or'gap 66, FIG. 3, through which pressure fluid may flow to and from the cylinder 30 of said first fluid motor means. The said bore 62 communicates with a bore 67 that in turn communicates with the lower end of the cylinder 40 whereby pressure fluid may flow to and from said second fluid motor means 37. The feed slide impact buffer cylinder 46 communicates with said annular groove 63 in the piston rod 22 through a very small diameter bore 70, the enlarged outer end thereof being closed by a threaded screw 71 having a head 72 that is disposed for feed slide guiding movement in a groove 73 formed in the adjacent side of the rod 11. It will thus be seen that when fluid pressure is supplied through the flexible tubing 60 the following sequence of events will occur: (1) the fluid motor means 37 will actuate the stock-gripping means 25 so that the latter grips the stock diagrammatically indicated at 74 of FIGS. 1- 4, (2) the main fluid motor means 15 will advance the feed slide and the gripped stock in a feed direction 31 until the cap 23 engages the web surface of the channel iron 13, and (3) the buffer piston rod 50 will.be displaced forwardly to an impact cushioning position as illustrated in FIGS. 1 and 3 preparatory to cushioning the terminal portion of the feed stock of slide 24,. Conversely when fluid pressure is exhausted from said tubing 60 the stock-gripping means will be released the buffer piston will be no longer biased in a forward direction and the fluid pressure in the feed cylinder 30 will flow out through annular gap es, holes 64, 65 and groove 63 to bore so that the spring 33 will retract the feed slide 24 in an index direction 32 into stroke determining engagement with the forward end of the adjustably positioned cylinder barrel 16. If desired the rate of flow of fluid pressure through bore 62 may be controlled by the provision of a variable restriction or needle valve as indicated by the small dotted line circle shown along the bore 62, H6. 2; such being well understood in the art. Any suitable stock guide means may be provided such as rollers 75 that are rotatably mounted on screws 76 that are laterally adjustably secured in the slot 77 formed in said angle iron or block 14, this guide roller arrangement also being well understood in the art.

The means for controlling the supply and exhaust of fluid pressure to and from the flexible tubing 60 includes a normally conducting three-way valve unit 80. The construction and mounting arrangement for this unit is particularly significant because it serves two functions, namely (1) the above-noted valving control function for said flexible tubing 60, and (2) an appropriate stock-clamping function that should occur during the time that feed slide 24 is moving in said nonfeeding or index direction 32. This stock-clamping function is a requirement in the operation of most reciprocating-type feeders so as to hold the stock from random movement while the feed slide is moving through its said nonfeeding stroke. Referring particularly to FIG. 4 the valve unit 80 comprises a cylindrical barrel 8] which is closed at its lower end by a cap screw 82 and which has an apertured cap screw 83 secured to its upper end. In the valve cylinder 84 there is disposed a valving member 85 that is axially slidably mounted on the lower reduced end of a valve stem 86 that extends upwardly through said cap screw 83. Suitable O-ring sliding seals are provided between the valve member 85 and the walls of cylinder 84, and between the valve stem 86 and said valve member 85.

Threadedly coupled to the lower side portion of the valve barrel is a fitting 87 that extends through a vertical slot 90 formed in a mounting bracket 9i and also through a suitable spacing washer 92. A supply hose 93 isoperatively connected between said fitting 87 and a source 94 of fluid pressure so as to thereby continuously supply fluid pressure to the valve barrel 81 there is threadedly secured a second fitting 95 that extends through another vertical slot 96 in said mounting bracket 91 and also through a suitable spacing washer 97. The said flexible tubing 60 is operatively connected to said fitting 595 so that said three-way valve unit 88 may control the flow of fluid pressure to and from said line or tubing 60. The horizontal leg of said valve unit mounting bracket 91 is formed with an open ended slot 100, FIGS. l and 4 in which is disposed a clamping screw Bill that threadedly engages the upper flange of the channel iron block 13 so as to be capable of securing the bracket 91 in adjusted position on said block 13. The channel iron block 13 has vertical mounting holes 103 and 104 FIG. 1, formed in the flanges thereof for mounting the feeder on the bed B, FIG. 3, of the press, hole 184 being aligned with said bracket slot 100, as may be seen in FIG. i, so that the associated feeder mounting bolt will assist in clamping said bracket 91 in its operative position shown.

The fluid pressure continuously present in the lower part of the valve cylinder 84 normally biases said valve member 85 and stem 86 to their respective uppermost positions shown in H6. 4. The uppermost position of the valving member 85 is determined by engagement of the upper gasket carrying surface of the valve member with the adjacent lower surface of the valve cap screw 33, such engagement thereby blocking the exhaust of fluid pressure from the valve unit through exhaust holes 110 and ill formed through said cap screw 83. The said normal or uppermost position of valve stem 86 is determined by engagement of a suitable I13 pin mounted on the lower reduced end of said stem with the lower surface of said valving member 85. In this normal condition of the valve unit elements fluid pressure from the lower cylinder portion 84 is conducted through the central bore H4 in the valve member 35 through the diametral hole 115 and into the annular space H6 afforded by the reduced upper end of valve member 85. From the annular space M6 the fluid pressure is conducted through fitting '95 and tubing 60 to the feed slide 24 so as to operate the said first and second fluid motor means and buffer means and thus produce a stock-feeding stroke of the feeder as above described. Thus in its normal condition the three-way valve unit supplies fluid pressure to tubing 60 and the feed slide 24 is in its forward position wherein said cap 23 engages the web of channel iron block 13.

In the other operative condition of said valve unit 88 fluid pressure is exhausted from tube 60 so as to produce an index stroke of the feed slide as will now be described. The valve stem 86 is provided with two operative shoulders 117 and 120, the shoulder 117 serving to permit and prevent the flow of fluid pressure into diametral hole 115, and shoulder 120serving to control the movement of valve member relative to the cap screw 83 so as to prevent or permit the flow of fluid pressure out through the exhaust holes and 111. In the operation of valve unit 80 when the valve stem 86 is moved downwardly relative to the cap 83, by means of a well-known type of vertically adjustable bolt mounted on the press ram and against the upward biasing action of the fluid pressure in cylinder 84, the movement of said stem relative to valve member 85 will first cause the shoulder 117 to move across and then block the diametral hole in said valve member 85. Continued downward of stem 86 causes shoulder to engage the upper gasketed surface of valve member 85 so as to displace the latter downwardly and thus.uncover the exhaust holes 110 and 111. By this valving action the supply of fluid pressure from cylinder 84 to the valve space 116 is cut mitted to rise the fluid pressure in cylinder 84 restores stem 86 r and valve member 85 to their said normal elevated conditions so that exhaust holes 110, ll! are again blocked and fluid pressure is again supplied to tubing 60 whereby a stock feeding stroke of the feeder is produced.

As may be seen from FIG. 4 the valve unit 80 is mounted on bracket 91 by means of said valve fittings 87 and 95 which extend through the vertical bracket slots 98 and 96 respectively, the lower end cap 82 of the valve unit 80 thus normally resting on top of the strip stock 74 to be fed. By this arrangement the lower cap screw 82 will be immediately pressed into a clamping condition with said stock when any valve-operating force is applied by the press ram to depress the valve stem 86. By this clamping action responsive to a depression of stem 86 the stock 74 will be held stationary between cap 82; and block i3 during the time that the valve stem is in a depressed condition and while the feed slide 24 is thus moving through its nonfeeding or index stroke in direction 32,FIG. ll. When said valve stem 86 moves back to its said normal elevated condition the stock-clamping action of the valve unit 88 will thus be released and the feed slide 24: will be advanced through its stock feeding stroke in direction 31, FIG. it it will thus be seen that the valve unit 80 performs its two noted functions. namely the fluid-valving function of supplying and exhausting fluid pressure to and from tube 60, and secondly the stock-clamping function which is properly synchronized with said valving function. The size of the clamping force exerted on stock 74 will be substantially determined by the product of the crosssectional area of said cylinder 84 times the fluid pressure in said cylinder.

lt will be noted that the valve unit 80 together with the bracket 91 may be readily detached from or attached to theinstant feeder merely by adjusting the mounting bolts and/or screws in the bracket slot 100 and uncoupling the fittings 6i and 87. In this way the valve unit 80 and associated 91 may be readily used with different feeders of the instant type.

It will be noted that the relatively few parts of the instant feeder are relatively unexpensive and most may be made by automatic screw machines. Further in that (1) both the valving and stock clamping functions are afforded by a single unit 80, (2) a minimized amount of fluid conduit means are used, and (3) a simplified stroke adjusting mounting of the main barrel 16 on the rod 12 are provided, the instant feeder is very simple structurally and such affords a drastic reduction in cost.

FIG. 6 illustrates a slightly modified embodiment of the instant invention, this modified feeder being the same in all respects as that shown and described in connection with FIGS. 1-5 except that the second fluid motor means 37' for operating the stock-gripping means 25 comprises a hydraulic motor 130 that is operated by an air motor 131. Here a single-acting, air-operated piston 132 actuates a small integral hydraulic pumping plunger 133 so as to thereby hydraulically actuate the larger hydraulic piston 134. The air motor 131 is operated through an air line 60' corresponding to line 60 of FIG. 1. This pneumatic-hydraulic action affords a large mechanical advantage and is intended for use in feeders where large stockgripping forces are required.

In FIGS. 1--5 the valve unit 80 is shown mounted on the feeder frame 10, however this unit may be operatively mounted on the press bed or on the press ram in a position so as to be able to correspondingly clamp the stock to be fed. in FIG. 7 the valve unit 80 is shown adjustably secured, by means of a threaded extension of the valve stem, on a bracket 135 that is fixed to the press ram 136. This type of arrangement may be'used to afford the same type of synchronized stock clamping and fluid valving action as that described above.

Since many changes could be made in the embodiments of the invention particularly described 'and shown herein without departing from the scope of the invention, it is intended that these embodiments be considered as exemplary and that the invention not be limited except as warranted by the following claims.

lclaim:

l. A stock feeder adapted to be operated through alternate indexing and stock-feeding strokes so as to intermittently advance stock into a punch press and the like comprising:

a frame;

a feed slide carried by said frame for reciprocation in index and feed directions;

stock-gripping means mounted on said feed slide and adapted to be moved between stock-gripping and stock release positions;

fluid motor means for actuating said feed slide and said stock-gripping means;

a valve unit for controlling the operation of said fluid motor means, said valve means having two operative valving conditions; and

mounting means for said valve unit which permits said unit to be placed in a stock-clamping condition and in a stockreleasing condition when said valve unit is shifted respectively from and to one of its said two operative valving conditions whereby the force required to operate said valve unit is applied as a clamping force to said stock to hold the latter stationary relative to said frame when said feed slide moves in said index direction.

2. Apparatus as defined by claim 1 wherein said valve unit is normally biased to said one operative condition so as to cause said feeder to partake of a stock-feeding stroke, there being substantially no clamping force existent when said valve unit is in said one operative condition.

3. Apparatus as defined by claim 1 wherein said fluid motor means includes a first fluid motor means for actuating said feed slide and a second fluid motor means for actuating said stock-gripping means, and wherein when said valve unit is in its normal condition said feed slide partakes of a stock-feeding stroke.

4. Apparatus as defined by claim 1 wherein said valve unit is mounted on said feeder frame.

5. Apparatus as defined by claim 1 wherein said valve unit is adapted to be mounted on said punch press.

6. Apparatus as defined by claim 1 wherein said frame includes a rod, and wherein said fluid motor means includes a cylinder, a tubular piston, and a tubular piston rod that are mounted on and around said rod, said piston, piston rod and cylinder being adapted to actuate said feed slide.

7. Apparatus as defined by claim 1 wherein said stockgripping means includes a lever means that is swingahly mounted on said feed slide. one end of said lever means being adapted to grip said stock while the other end of said lever means is adapted to be operated by said fluid motor means.

8. Apparatus as defined by claim 1 wherein said fluid motor means includes a first and a second fluid motor means, said second motor means being adapted to actuate said stockgripping means and comprising a hydraulic motor, a hydraulic pumping plunger means for operating said hydraulic motor, and air motor means for actuating said hydraulic-pumping plunger means whereby high stock-gripping forces may be generated.

9. A stock feeding device for intermittently advancing stock into a work station comprising:

a frame having at least one side rod;

a feed slide adapted to be reciprocated in index and stock feed directions;

stock-gripping means mounted on said feed slide and adapted to be operated between stock-gripping and stock-releasing positions;

fluid motor means for actuating said feed slide and stockgripping means, said fluid motor means including:

a cylinder barrel mounted substantially coaxially with respect to said slide rod;

a tubular piston slidably mounted in said cylinder barrel;

a'tubular piston rod operatively connected to said tubular piston and being disposed over said slide rod and for axial movement along said rod, said slide rod extending completely through said cylinder barrel, said piston, said piston rod and said feed slide; and

valve means for controlling the operation of said fluid motor means.

10. Apparatus as defined by claim 9 wherein annular gap is provided between said slide rod and the inside of said tubular piston rod, through which gap fluid pressure may operatively flow to and from said cylinder barrel.

11. Apparatus as defined by claim 9 wherein said cylinder barrel is adjustably mounted on said rod so as to effectively determine the operative length of the feed stroke of said feed slide.

12. Apparatus as defined by claim 9 wherein said fluid motor means includes a separate fluid motor means that is mounted on said feed slide and is adapted to actuate said stock-gripping means.

13. Apparatus as defined by claim 9 wherein said valve means includes a fluid conduit means that is connected to said feed slide, and wherein said feed slide is formed with a fluidconducting passage that communicates with both said fluid conduit means and said fluid motor means whereby said valve means controls the operation of said fluid motor means by supplying and exhausting fluid pressure through said fluidconducting passage formed in said feed slide.

14. A stock feeder adapted to be operated through alternate indexing and stock-feeding stroke so as to intermittently advance stock into a work station comprising:

a frame;

a feed slide carried by said frame for reciprocation in index and feed directions;

stock-gripping means mounted on said feed slide and being adapted to be moved between stock-gripping and stockreleasing positions;

fluid motor means for actuating said feed slide and said stock-gripping means, said fluid motor means including a fluid motor that is adapted to actuate said feed slide;

said feed slidebeing formed with a fluid-conducting passage that communicates with said fluid motor means;

valve means for controlling the flow of fluid pressure to and from said fluid motor means; and

fluid conduit tubing connected externally of said fluid motor between the relatively movable feed slide and said valve means so that fluid pressure to be supplied and exhausted under the control of said valve means to and from said fluid motor means passes through said fluid conduit tubing and through the said fluid-conducting passage formed in said feed slide.

15. Apparatus as defined by claim 14 wherein said valve means has two operative valving conditions and is mounted so as to be placed in stock-releasing and stock-clamping positions when said valve means is shifted respectively to and from one of its said two operative valving conditions whereby the force required to operate said valve means is applied as a clamping force to said stock to hold the latter stationary during an indexing stroke of said stock-feeding device.

lloApparatus as defined by claim 14 wherein said feed slide is continuously biased in an index direction, and is actuated in the opposite direction by said fluid motor means; wherein said valve means comprises a three-way valve; and wherein said fluid conduit means comprises a length of flexible tubing that is connected between said three-way valve and said fluid-conducting passage of said feed slide so that the fluid pressure to be supplied and exhausted to and from said fluid motor means passes through said tubing.

?7. Apparatus as defined by claim 14 wherein said valve mt ans is normally biased to a first operative condition in which fluid pressure is normally supplied to said fluid motor means so that stock-feeding device thereby partakes of a stock-feeding stroke.

18. Apparatus as defined by claim 15 wherein said frame in cludes at least one slide rod, and wherein said fluid motor means includes a cylinder barrel, a tubular piston slidably disposed in said barrel and a tubular piston rod that is connected to said piston and is mounted for movement along said slide rod, said barrel, piston and piston rod being adapted to actuate said feed slide.

19. Apparatus as defined by claim 14 wherein said fluid motor means comprises a first and a second fluid motor means, said first fluid motor means being adapted to actuate said feed slide, while said second fluid motor means is arranged so as to actuate said stock-gripping means.

20. A stock-feeding device adapted to be operated through alternate indexing and stock-feeding strokes so as to intermittently advance stock into the work station of punch presses and the like comprising:

a frame including at least one side rod;

:1 first fluid motor means mounted on said rod, said motor means including:

a cylinder barrel mounted on said rod and being movable to variable adjusted positions along said rod so as to effectively determine the length of the feed stroke of said stock-feeding device;

locking means for securing said cylinder barrel in adjusted position on said slide rod;

a tubular piston slidably mounted in said cylinder barrel and being disposed around said rod; and

a tubular piston rod disposed around said rod and for movement along said rod and being connected to one end thereof to said piston;

a feed slide secured to the other end of said piston rod;

stock-gripping means mounted on said feed slide and adapted to be moved between stock-gripping and stockreleasing positions;

a second fluid motor means for actuating said stockgripping means;

said feed slide being formed with a fluid-connecting passage that communicates with said second fluid motor means and, through said tubular piston and piston rod, with said first fluid motor means;

a fluid conduit line operatively coupled at one end thereof with said fluid-conducting passage of said feed slide;

a valve unit having a control port that is operatively coupled to the other end of said fluid conduit line, said valve unit being operative in a first valving condition to supply fluid pressure through said conduit line to said first and second fluid motor means, and operative in a second valving condition to exhaust fluid pressure through said conduit line from said first and second fluid motor means; and mounting means for said valve unit for permitting said value unit to be placed in stock-clamping and stock-releasing conditions when said valve unit is shifted respectively from and to one of its said two operative valving conditions whereby the force required to operate said valve unit is applied as a clamping force to said stock to hold the latter stationary relative to said stock-feeding device.

21. Apparatus as defined by claim 29 wherein said valve unit is mounted on said frame, wherein said valve unit when in said first operative condition produces a stock-feeding stroke of said feeding device, and wherein said fluid conduit line comprises a length of flexible tubing.

22. Apparatus as defined by claim 20 wherein spring means are provided for biasing said feed slide in an indexing direction.

23. Apparatus as defined by claim 1 wherein said valve unit is detachable from said frame and is operative when attached or detached to control the operation of said fluid motor means, and wherein a variably positionable tubing is interposed in the connection between said valve unit and said fluid motor means.

24. Apparatus as defined by claim 1 wherein said fluid motor means includes a fluid motor that is operable to displace said feed slide in a stock feed direction.

25. Apparatus as defined by claim 1 wherein said valve means includes a fluid conduit means that is connected to said feed slide, and wherein said feed slide is formed with a fluidconducting passage that communicates with both said fluid conduit means and said fluid motor means whereby said valve means controls the operation of said fluid motor means by supplying and exhausting fluid pressure through said fluidconducting passage formed in said feed slide.

26. Apparatus as defined by claim 1 wherein said mounting means is adapted to mount said valve unit so as to move with the ram of said press.

27. A stock feeder for intermittently advancing stock into the work station ofa punch press or the like comprising:

a stock-feeding portion and a stock-clamping portion. said portions being mutually separable;

said stock feeding portion including:

a frame;

a feed slide mounted for reciprocation on said frame in index and feed directions;

stock-gripping means carried by said feed slide; and

power means for actuating said feed slide and stockgripping means to effect a stock-feeding stroke of said feeder;

said separable stock-clamping portion including a pistoncylinder unit adapted to have fluid pressure supplied to one operative end thereof so as to continuously bias said unit to an extended condition, said piston-cylinder unit being adapted to be mechanically operated by said press so as to assume a contracted condition;

mounting means for mounting said stock-clamping portion whereby the said operation of said stock-clamping portion to a contracted condition by the press causes a corresponding clamping force to be applied to the stock during an index stroke of said feeder; and

control means for controlling the operation of said power means.

28. Apparatus as defined by claim 27 wherein said control means is included in said stock-clamping portion and comprises a valve means and a conduit means therefrom that is coupled to said feed slide.

2?. Apparatus as defined by claim 28 wherein said power means includes fluid motor means, and wherein said conduit means includes variably positionable tubing which interconnects said valve means and said fluid motor means.

30. Apparatus as definedby claim 27 wherein said stockclarnping portion is mounted on said press.

31. Apparatus as defined by claim 27 wherein said stockclamping means is mounted on said frame of said stock-feeding portion.

32. in a stock feeder for intermittently advancing stock into the work station of a punch press or the like comprising;

mounting means for mounting said three-way valve means so that when said valve means is shifted to a second operative condition thereof by the operation of said press and against said biasing action said unit is thereby pressed against said stock so as to immobilize the latter and to cause said stock-feeding means to partake of an indexing stroke.

33. Apparatus as defined by claim 32 wherein the output port from said three-way valve means is connected by variably positionable external tubing to said stock-feeding means.

34. Apparatus as defined by claim 32 wherein said stock clamping and valving unit is detachably mounted on said frame, wherein flexible tubing is provided to interconnect said unit and said fluid motor means, and wherein said stock-feeding means is caused to partake of a feed stroke when said vale means is in its said first operative condition.

35. Apparatus as defined by claim 32 wherein said stock clamping and valving unit is mounted on said press. 

1. A stock feeder adapted to be operated through alternate indexing and stock-feeding strokes so as to intermittently advance stock into a punch press and the like comprising: a frame; a feed slide carried by said frame for reciprocation in index and feed directions; stock-gripping means mounted on said feed slide and adapted to be moved between stock-gripping and stock release positions; fluid motor means for actuating said feed slide and said stockgripping means; a valve unit for controlling the operation of said fluid motor means, said valve means having two operative valving conditions; and mounting means for said valve unit which permits said unit to be placed in a stock-clamping condition and in a stock-releasing condition when said valve unit is shifted respectively from and to one of its said two operative valving conditions whereby the force required to operate said valve unit is applied as a clamping force to said stock to hold the latter stationary relative to said frame when said feed slide moves in said index direction.
 2. Apparatus as defined by claim 1 wherein said valve unit is normally biased to said one operative condition so as to cause said feeder to partake of a stock-feeding stroke, there being substantially no clamping force existent when said valve unit is in said one operative condition.
 3. Apparatus as defined by claim 1 wherein said fluid motor means includes a first fluid motor means for actuating said feed slide and a second fluid motor means for actuating said stock-gripping means, and wherein when said valve unit is in its normal condition said feed slide partakes of a stock-feeding stroke.
 4. Apparatus as defined by claim 1 wherein said valve unit is mounted on said feeder frame.
 5. Apparatus as defined by claim 1 wherein said valve unit is adapted to be mounted on said punch press.
 6. Apparatus as defined by claim 1 wherein said frame includes a rod, and wherein said fluid motor means includes a cylinder, a tubular piston, and a tubular piston rod that are mounted on and around said rod, said piston, piston rod and cylinder being adapted to actuate said feed slide.
 7. Apparatus as defined by claim 1 wherein said stock-gripping means includes a lever means that is swingably mounted on said feed slide, one end of said lever means being adapted to grip said stock while the other end of said lever means is adapted to be operated by said fluid motor means.
 8. Apparatus as defined by claim 1 wherein said fluid motor means includes a first and a second fluid motor means, said second motor means being adapted to actuate said stock-gripping means and comprising a hydraulic motor, a hydraulic pumping plunger means for operating said hydraulic motor, and air motor means for actuating said hydraulic-pumping plunger means whereby high stock-gripping forces may be generated.
 9. A stock feeding device for intermittently advancing stock into a work station comprising: a frame having at least one side rod; a feed slide adapted to be reciprocated in index and stock feed directions; stock-gripping means mounted on said feed slide and adapted to be operated between stock-gripping and stock-releasing positions; fluid motor means for actuating said feed slide and stock-gripping means, said fluid motor means including: a cylinder barrel mounted substantially coaxially with respect to said slide rod; a tubular piston slidably mounted in said cylinder barrel; a tubular piston rod operatively connected to said tubular piston and being disposed over said slide rod and for axial movement along said rod, said slide rod extending completely through said cylinder barrel, said piston, said piston rod and said feed slide; and valve means for controlling the operation of said fluid motor means.
 10. Apparatus as defined by claim 9 wherein annular gap is provided between said slide rod and the inside of said tubular piston rod, through which gap fluid pressure may operatively flow to and from said cylinder barrel.
 11. Apparatus as defined by claim 9 wherein said cylinder barrel is adjustably mounted on said rod so as to effectively determine the operative length of the feed stroke of said feed slide.
 12. Apparatus as defined by claim 9 wherein said fluid motor means includes a separate fluid motor means that is mounted on said feed slide and is adapted to actuate said stock-gripping means.
 13. Apparatus as defined by claim 9 wherein said valve means includes a fluid conduit means that is connected to said feed slide, and wherein said feed slide is formed with a fluid-conducting passage that communicates with both said fluid conduit means and said fluid motor means whereby said valve means controls the operation of said fluid motor means by supplying and exhausting fluid pressure through said fluid-conducting passage formed in said feed slide.
 14. A stock feeder adapted to be operated through alternate indexing and stock-feeding stroke so as to intermittently advance stock into a work station comprising: a frame; a feed slide carried by said frame for reciprocation in index and feed directions; stock-gripping means mounted on said feed slide and being adapted to be moved between stock-gripping and stock-releasing positions; fluid motor means for actuating said feed slide and said stock-gripping means, said fluid motor means including a fluid motor that is adapted to actuate said feed slide; said feed slide being formed with a fluid-conducting passage that communicates with said fluid motor means; valve means for controlling the flow of fluid pressure to and from said fluid motor means; and fluid conduit tubing connected externally of said fluid motor between the relatively movable feed slide and said valve means so that fluid pressure to be supplied and exhausted under the control of said valve means to and from said fluid motor means passes through said fluid conduit tubing and through the said fluid-conducting passage formed in said feed slide.
 15. Apparatus as defined by claim 14 wherein said valve means has two operative valving conditions and is mounted so as to be placed in stock-releasing and stock-clamping positions when said valve means is shifted respectively to and from one of its said two operative valving conditions whereby the force required to operate said valve means is applied as a clamping force to said stock to hold the latter stationary during an indexing stroke of said stock-feeding device.
 16. Apparatus as defined by claim 14 wherein said feed slide is continuously biased in an index direction, and is actuated in the opposite direction by said fluid motor means; wherein said valve means comprises a three-way valve; and wherein said fluid conduit means comprises a length of flexible tubing that is connected between said three-way valve and said fluid-conducting passage of said feed slide so that the fluid pressure to be supplied and exhausted to and from said fluid motor means passes through said tubing.
 17. Apparatus as defined by claim 14 wherein said valve means is normally biased to a first operative condition in which fluid pressure is normally supplied to said fluid motor means so that stock-feeding device thereby partakes of a stock-feeding stroke.
 18. Apparatus as defined by claim 15 wherein said frame includes at least one slide rod, and wherein said fluid motor means includes a cylinder barrel, a tubular piston slidably disposed in said barrel and a tubular piston rod that is connected to said piston and is mounted for movement along said slide rod, said barrel, piston and piston rod being adapted to actuate said feed slide.
 19. Apparatus as defined by claim 14 wherein said fluid motor meaNs comprises a first and a second fluid motor means, said first fluid motor means being adapted to actuate said feed slide, while said second fluid motor means is arranged so as to actuate said stock-gripping means.
 20. A stock-feeding device adapted to be operated through alternate indexing and stock-feeding strokes so as to intermittently advance stock into the work station of punch presses and the like comprising: a frame including at least one side rod; a first fluid motor means mounted on said rod, said motor means including: a cylinder barrel mounted on said rod and being movable to variable adjusted positions along said rod so as to effectively determine the length of the feed stroke of said stock-feeding device; locking means for securing said cylinder barrel in adjusted position on said slide rod; a tubular piston slidably mounted in said cylinder barrel and being disposed around said rod; and a tubular piston rod disposed around said rod and for movement along said rod and being connected to one end thereof to said piston; a feed slide secured to the other end of said piston rod; stock-gripping means mounted on said feed slide and adapted to be moved between stock-gripping and stock-releasing positions; a second fluid motor means for actuating said stock-gripping means; said feed slide being formed with a fluid-connecting passage that communicates with said second fluid motor means and, through said tubular piston and piston rod, with said first fluid motor means; a fluid conduit line operatively coupled at one end thereof with said fluid-conducting passage of said feed slide; a valve unit having a control port that is operatively coupled to the other end of said fluid conduit line, said valve unit being operative in a first valving condition to supply fluid pressure through said conduit line to said first and second fluid motor means, and operative in a second valving condition to exhaust fluid pressure through said conduit line from said first and second fluid motor means; and mounting means for said valve unit for permitting said value unit to be placed in stock-clamping and stock-releasing conditions when said valve unit is shifted respectively from and to one of its said two operative valving conditions whereby the force required to operate said valve unit is applied as a clamping force to said stock to hold the latter stationary relative to said stock-feeding device.
 21. Apparatus as defined by claim 20 wherein said valve unit is mounted on said frame, wherein said valve unit when in said first operative condition produces a stock-feeding stroke of said feeding device, and wherein said fluid conduit line comprises a length of flexible tubing.
 22. Apparatus as defined by claim 20 wherein spring means are provided for biasing said feed slide in an indexing direction.
 23. Apparatus as defined by claim 1 wherein said valve unit is detachable from said frame and is operative when attached or detached to control the operation of said fluid motor means, and wherein a variably positionable tubing is interposed in the connection between said valve unit and said fluid motor means.
 24. Apparatus as defined by claim 1 wherein said fluid motor means includes a fluid motor that is operable to displace said feed slide in a stock feed direction.
 25. Apparatus as defined by claim 1 wherein said valve means includes a fluid conduit means that is connected to said feed slide, and wherein said feed slide is formed with a fluid-conducting passage that communicates with both said fluid conduit means and said fluid motor means whereby said valve means controls the operation of said fluid motor means by supplying and exhausting fluid pressure through said fluid-conducting passage formed in said feed slide.
 26. Apparatus as defined by claim 1 wherein said mounting means is adapted to mount said valve unit so as to move with the ram of said press.
 27. A stock feeder for intermittently advanCing stock into the work station of a punch press or the like comprising: a stock-feeding portion and a stock-clamping portion, said portions being mutually separable; said stock feeding portion including: a frame; a feed slide mounted for reciprocation on said frame in index and feed directions; stock-gripping means carried by said feed slide; and power means for actuating said feed slide and stock-gripping means to effect a stock-feeding stroke of said feeder; said separable stock-clamping portion including a piston-cylinder unit adapted to have fluid pressure supplied to one operative end thereof so as to continuously bias said unit to an extended condition, said piston-cylinder unit being adapted to be mechanically operated by said press so as to assume a contracted condition; mounting means for mounting said stock-clamping portion whereby the said operation of said stock-clamping portion to a contracted condition by the press causes a corresponding clamping force to be applied to the stock during an index stroke of said feeder; and control means for controlling the operation of said power means.
 28. Apparatus as defined by claim 27 wherein said control means is included in said stock-clamping portion and comprises a valve means and a conduit means therefrom that is coupled to said feed slide.
 29. Apparatus as defined by claim 28 wherein said power means includes fluid motor means, and wherein said conduit means includes variably positionable tubing which interconnects said valve means and said fluid motor means.
 30. Apparatus as defined by claim 27 wherein said stock-clamping portion is mounted on said press.
 31. Apparatus as defined by claim 27 wherein said stock-clamping means is mounted on said frame of said stock-feeding portion.
 32. In a stock feeder for intermittently advancing stock into the work station of a punch press or the like comprising; a frame; reciprocating stock-feeding means including fluid motor means mounted on said frame and adapted to advance the stock to be fed in a feed direction; a stock-clamping and valving unit for controlling said stock-feeding means and for clamping said stock during movement of said stock-feeding means in an indexing direction; said stock clamping and valving unit including a three-way valve means that is adapted to control the operation of said stock-feeding means and to be biased towards a first operative condition thereof wherein said stock-feeding means is caused to partake of a stock-feeding stroke; and mounting means for mounting said three-way valve means so that when said valve means is shifted to a second operative condition thereof by the operation of said press and against said biasing action said unit is thereby pressed against said stock so as to immobilize the latter and to cause said stock-feeding means to partake of an indexing stroke.
 33. Apparatus as defined by claim 32 wherein the output port from said three-way valve means is connected by variably positionable external tubing to said stock-feeding means.
 34. Apparatus as defined by claim 32 wherein said stock clamping and valving unit is detachably mounted on said frame, wherein flexible tubing is provided to interconnect said unit and said fluid motor means, and wherein said stock-feeding means is caused to partake of a feed stroke when said vale means is in its said first operative condition.
 35. Apparatus as defined by claim 32 wherein said stock clamping and valving unit is mounted on said press. 